Spark-plug tester



June 17, 1930.

SPARK PLUG TESTER F 8d D80. 26, 1923 /2 /7 I 1 v 6cm new A. c. EKLE 1,764,248

Patented June 17, 1930 UNITED STATES ALEXANDER C. EKLE, F MANKATO, MINNESOTA SPARK-PLUG TESTER Application filed December 26, 1923. Serial No. 682,736. I

This invention relates to testers for spark plugs of internal combustion engines.

The object of the invention is to provide a simple and eficient device of this character constructed so as to test the plug under pressure.

It is well known that spark plugs which will function under atmospheric pressure will not always fire when in use owing to the pressure in the engine cylinder which retards sparking. character to properly perform its function under pressure in the cylinder requires that it be of a high degree of perfection.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without-'cleparting from the spirit of the invention.

In the accompanying drawings:

Figure 1 represents a plan view of a spark coil and casing with the plug carrying member removed.

Fig. 2 represents a side elevation of the apparatus complete with parts broken out and a plug shown applied.

Fig. 3 is a detail longitudinal section.

Fig. 4 is a diagram illustrating the manner of positioning the spark plug carrying member on the casing.

In the embodiment illustrated the device constituting this invention comprises a casing 1 preferably composed of wood or other non-conducting material in which a spark coil as shown at 2 is mounted and which has contacts 3 and 4 located in its topwith bolts 5 and 6 extending through opposite sides of the casing and engaged with said contacts, said bolt 5 being designed to support a metal cyl- 45 inder 10. The bolt 7 is in circuit with the positive pole of the spark coil supported within the casing, while the bolt 7' extending through the opposite end of the casingis in circuit with the contact 3 or the negative pole 5 of the spark coil through the buzzer thereof.

Hence to enable a plug of this der.

A wire 8 connecting said bolt 7 with another bolt 9 mounted in one side wall of the casing and on which is mounted twohook-shaped terminals 11 and 12' to be connected with one of the poles of a battery while bolt 7 is placed i circuit with the opposite pole] of the batery.

A wire 13 connects bolt 6 with the plug to be tested as will be presently more fully described. i

The metal cylinder 10 which is designed to be mounted in the casing 1 is closed at one end by a bushing 14 having a transparent partition 15 secured between its inner end and a shoulder 16 formed at one end of the cylin G5 der, said partition having an air tight connection, gaskets 17 being arranged between said partition and the shoulder 16 and the bushing. This partition 15 forms a sight opening for inspection of the plug 18 to be, tested which is mounted in the opposite end of the cylinder and which has an airtight connection therewith, a copper gasket 19 being provided for this purpose. A valve is mounted in a stem or tube 20 which extends from the upper portion of the cylinder 10 and communicates with its interior. This valve is similar to that used on a pneumatic tire and is designed for inserting air under pressure into the cylinder to provide for the testing of the plug under compression.

In the use of this tester a spark plug 18 is inserted in the open end of cylinder 10 and a pump or other compressed air supplying device connected with the valved tube 20 and air under pressure is pumped into said cylinder until pounds pressure more or less is reached. The cylinder 10 is then inserted in the casing 1 resting on the bolt 5 and the Wire 13 is connected with the plug. The hooked members 11 and 12 are connected to a battery terminal. Current is thus supplied for firing the plug and by looking through the sight glass 15 will disclose whether the A plug is firing under the pressure in the cylin 95 It is of course understood that the amount of pressure in the cylinder may be tested by a gauge such as a tire gauge.

If the plug is in proper condition for use in an engine cylinder, the proper sparking or arcing result between the electrodes will be observed.

Various changes in the form, shape, proportion and other minor details of construc- 5 tion may be made Without departing from the principle or sacrificing any of the advantages of the claimed invention.

I claim A spark plug tester embodying a casing,

a spark coil mounted Within the casing and having contact points and having a buzzer, a bolt extending through the casing and contacting with one of the contact points of the spark coil, a bolt extending through the op- 5 posite side of the casing-and engaging another contactpoint-ofthe spark coil, a boltextenolthrough one end of the casing and in circuit with the buzzer of the spark .coil, 21 wire leading "from the first mentioned bolt to a spark p1 ug,-a plug supporting cylinder in which the vspark ,plug is positioned, said plug supporting cylinder adapted to rest the second mentioned bolt .toground the ciruit passingto the spark plug, andsaid plug supporting cylinder having a sight opening in one end thereof.

In testimony that I claim the foregoing as .my own, .I have hereto affixed my signature.

0 C. ,EKLE. 

